中国农业科学 ›› 2026, Vol. 59 ›› Issue (1): 90-100.doi: 10.3864/j.issn.0578-1752.2026.01.007

• 植物保护 • 上一篇    下一篇

光合作用系统Ⅱ相关蛋白NbPsbQ1通过促进光合效率抑制病毒侵染

付涵(), 于杨, 艾妞, 张思晴, 于连伟, 孙书豪, 赵金章, 韩晓玉, 施艳, 杨雪*()   

  1. 河南农业大学植物保护学院,郑州 450046
  • 收稿日期:2025-08-29 接受日期:2025-10-05 出版日期:2026-01-01 发布日期:2026-01-07
  • 通信作者:
    杨雪,E-mail:
  • 联系方式: 付涵,E-mail:f2939735928@163.com。
  • 基金资助:
    河南省高校科技创新团队(25IRTSTHN031); 中原青年拔尖人才项目(30603407)

The Photosystem II Protein NbPsbQ1 Inhibits Viral Infection by Promoting Photosynthetic Efficiency

FU Han(), YU Yang, AI Niu, ZHANG SiQing, YU LianWei, SUN ShuHao, ZHAO JinZhang, HAN XiaoYu, SHI Yan, YANG Xue*()   

  1. College of Plant Protection, Henan Agricultural University, Zhengzhou 450046
  • Received:2025-08-29 Accepted:2025-10-05 Published:2026-01-01 Online:2026-01-07

摘要:

【背景】黄瓜绿斑驳花叶病毒(cucumber green mottle mosaic virus,CGMMV)是我国重要的检疫性植物病毒之一,主要侵染葫芦科作物,造成世界范围内葫芦科作物的严重减产。PsbQ(oxygen-evolving enhancer protein 3)蛋白是组成PSII复合物(OEC)的相关蛋白之一,参与PSII组装、稳定PSII功能,并对植物应对生物和非生物胁迫反应起调控作用。前期研究显示CGMMV侵染后可以显著下调寄主叶绿体调控基因NbPsbQ1的表达。【目的】明确NbPsbQ1参与CGMMV侵染的机制,为CGMMV病害防控提供理论依据。【方法】通过构建NbPsbQ1及CGMMV CP的荧光表达载体,转化GV3101农杆菌后浸润本氏烟叶片,激光共聚焦显微镜观察其亚细胞定位;利用qRT-PCR技术分析NbPsbQ1在CGMMV侵染不同时期和CP过表达后的转录水平;利用双分子荧光互补、免疫共沉淀和酵母双杂交试验分别验证NbPsbQ1与CP在体内及体外的互作;通过TRV沉默技术分析NbPsbQ1在CGMMV侵染过程中的作用;瞬时过表达NbPsbQ1进一步验证NbPsbQ1对CGMMV蛋白水平及转录水平的影响;测定NbPsbQ1沉默以及CGMMV侵染不同时间植株的光合效率指标,从而分析NbPsbQ1以及CGMMV对植株光合作用的影响。【结果】亚细胞定位结果显示NbPsbQ1定位于叶绿体,而CP定位于细胞质和细胞核;在CGMMV侵染以及CP过表达后,与对照相比,NbPsbQ1的转录水平均明显下调;双分子荧光互补和免疫共沉淀试验结果均证明NbPsbQ1与CP在体内互作,且两者互作使NbPsbQ1的定位从叶绿体迁移至细胞质,但酵母双杂交试验证明两者在植物体外不互作;在沉默植株上接种CGMMV,4 d后观察到处理组和对照组均有部分植株系统叶开始出现斑驳、卷曲症状,而TRV:NbPsbQ1组的发病植株数量始终多于对照组;同时检测mRNA水平和蛋白水平表达结果也表明NbPsbQ1的沉默有效促进了CGMMV的积累;NbPsbQ1瞬时过表达抑制CGMMV CP积累进一步证实NbPsbQ1抑制CGMMV侵染;测定NbPsbQ1沉默植株的光合效率指标,发现与对照组相比,NbPsbQ1沉默后显著降低植株叶片的净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr),胞间CO2浓度(Ci)明显升高,表明NbPsbQ1参与植株光合作用;同时,发现在CGMMV侵染9 d时,Gs、Tr明显下降而Ci升高。【结论】CGMMV CP与NbPsbQ1在体内互作,并改变其叶绿体定位;随着CGMMV不断侵染,光合作用系统II相关基因NbPsbQ1表达水平下调,光合效率受到抑制,从而促进病毒后期的积累。

关键词: 黄瓜绿斑驳花叶病毒, NbPsbQ1, 光合作用系统II, 光合作用, 致病机制

Abstract:

【Background】Cucumber green mottle mosaic virus (CGMMV) is one of the important quarantined plant viruses in China. It mainly infects Cucurbitaceae crops, causing severe yield losses of Cucurbitaceae crops worldwide. The PsbQ protein (oxygen-evolving enhancer protein 3) is one of the proteins associated with the photosystem II (PSII) oxygen-evolving complex (OEC). It is involved in PSII assembly, stabilizes PSII function, and regulates plant responses to biotic and abiotic stresses. Previous studies have shown that CGMMV infection can significantly downregulate the expression of the host chloroplast regulatory gene NbPsbQ1. 【Objective】This study aims to clarify the mechanism by which NbPsbQ1 participates in CGMMV infection and provide a theoretical basis for the prevention and control of CGMMV infection. 【Method】The expression vector of NbPsbQ1-GFP and CGMMV CP was constructed, transformed into Agrobacterium GV3101 and infiltrated the tobacco leaves to observe the subcellular localization of NbPsbQ1 by confocal microscopy. qRT-PCR was used to analyze the transcriptional levels of NbPsbQ1 at different stages of CGMMV infection and after CP overexpression. The interaction between NbPsbQ1 and CP in vivo and in vitro was verified using bimolecular fluorescence complementation (BiFC), co-immunoprecipitation (Co-IP), and yeast two-hybrid (Y2H) assays, respectively. TRV-mediated gene silencing (VIGS) was employed to investigate the role of NbPsbQ1 during CGMMV infection. Transient overexpression of NbPsbQ1 was used to further verify the effect of NbPsbQ1 on the protein level and transcriptional level of CGMMV. The photosynthetic efficiency indicators of plants were determined after NbPsbQ1 silencing and at different stages of CGMMV infection, the effects of NbPsbQ1 and CGMMV on plant photosynthesis were analyzed. 【Result】Subcellular localization results showed that NbPsbQ1 was localized in chloroplasts, while CP was localized in the cytoplasm and nucleus. After CGMMV infection or CP overexpression, the transcriptional level of NbPsbQ1 was significantly downregulated compared with the control. Results from both BiFC and Co-IP assays demonstrated that NbPsbQ1 interacts with CP in vivo. Furthermore, this interaction causes the subcellular localization of NbPsbQ1 to shift from chloroplasts to the cytoplasm. However, the yeast two-hybrid (Y2H) assay confirmed that the two proteins do not interact in vitro. CGMMV was inoculated into TRV:NbPsbQ1 and TRV:00 plants. Partial systemic leaves of plants in both the TRV:NbPsbQ1 and TRV:00 plants began to show mottling and curling symptoms at 4 dpi. However, the number of symptomatic plants was consistently higher in the TRV:NbPsbQ1 plants than that in the control plants. Meanwhile, detection of mRNA and protein expression levels also indicated that silencing NbPsbQ1 effectively promoted CGMMV accumulation. Transient overexpression of NbPsbQ1 inhibited the accumulation of CP, further confirming that NbPsbQ1 suppresses CGMMV infection. Silencing of NbPsbQ1 significantly reduced the net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) of plant leaves, while the intercellular CO2 concentration (Ci) increased significantly, indicating that NbPsbQ1 is involved in plant photosynthesis. Additionally, it was found that Gs and Tr decreased significantly, while Ci increased at 9 d during CGMMV infection. 【Conclusion】The CP of CGMMV interacts with NbPsbQ1 in vivo and alters its chloroplast localization. During the CGMMV infection, the expression level of NbPsbQ1 is downregulated, and photosynthetic efficiency is inhibited, thereby promoting the CGMMV accumulation in the late infection stage.

Key words: cucumber green mottle mosaic virus (CGMMV), NbPsbQ1, photosystem II (PSII), photosynthesis, pathogenic mechanism